<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="../js/jquery.js"></script>
<script type="text/javascript">
	function f1(){
		$('#form1 input:disabled').css('border','1px dotted red');
		
		$('#form1 input:disabled').attr('disabled',false);
	}
	
	function f2(){
		alert($('#form2 input:checked').val());
	}
	
	function f3(){
		alert($('#form3 option:selected').val());
	}
</script>
</head>
<body>
	<form id="form1">
		姓名:<input name="username" disabled="disabled"/><br/>
		真名:<input name="name"/><br/>
	</form>
	<form id="form2">
		兴趣爱好:
		做饭<input type="checkbox" value="cooking" name="interest"/>
		钓鱼<input type="checkbox" value="fishing" name="interest" checked="checked"/>
		旅游<input type="checkbox" value="traveling" name="interest"/>
	</form>
	<form id="form3">
		<select>
			<option value='bj'>北京</option>
			<option value='sh'>上海</option>
			<option value='nj' selected="selected">南京</option>
			<option value='sz'>苏州</option>
		</select>
	</form>
	<input type="button" value="点击" onclick="f3();"/>
</body>
</html>